Aaron's Clean Hands

Vayikra 9:22 "Aaron raised his hands toward the people and blessed them..."

It seems that there is special meaning behind this pasuk. Did Aaron arbitrarily decide that he wanted to bless Klal Yisrael? Was there any specific reason for it?

We see in Tractate Brachos (32b) "any Kohen who kills a person can not [duchan] raise his hands". Furthermore we know that Aaron took part in the golden calf, which caused many people from Klal Yisrael to die. How could he duchan afterwards?

One can answer that becuase it was an Ones, Aaron could not be held accountable for his actions for he feared that the idolators would have killed him like they did to Chur. Therefore Aaron was allowed to Duchan.

Rebbi Yosef Schwartz says that this is the reason for this pasuk. "Aaron raised his hands" to show Klal Yisrael that his hands were clean from murder, and that he was fully able to bless them through Bircas Kohanim.